Experimental study on mechanical properties and failure behavior analysis of CFRP riveted joints with gaskets and bushings

The application of gaskets, bushings or their combination can significantly improve the joining strength of composite structures, but there is still a lack of systematic researches on their combined or individual applications. To solve this problem, this paper reported a comparative assessment on the joint strength and failure behavior of carbon fiber reinforced polymer(CFRP) joints with different combination of gaskets and bushings, i.e., riveting, gasket riveting, bushing riveting and gasket-bushing riveting. The results show that gasket riveting can improve the ability of the joint to absorb energy and resist damage by increasing the load-bearing area and the extrusion deformation of the gasket, so that the joints can obtain the highest strength. This combination also limits secondary bending and delay the damage of the joints, the failure mode of the joints is extrusion failure. Besides, the size of the rivets used in bushing riveting is small, which leads to a decrease in the joint′s resistance to damage and energy absorption. The average joining strength of the specimens is minimal, and the failure mode is a mixed extrusion-pull-off failure. At last, although the gasket-bushing riveting method cannot improve the joints′ ability to resist damage, it can greatly improve the joint′s energy absorption capacity and joining strength.